CN100501164C - scroll compressor - Google Patents

Abstract

A scroll compressor, in which a fixed scroll member (2) and an orbiting scroll member (4) are engaged to form a compression chamber (5) between the two, and the fixed scroll member (2) and the orbiting scroll member (4) The scroll body is erected from the mirror plate, and the compression chamber (5) moves while changing the volume when the orbiting scroll member (4) is rotated in a circular orbit on the basis of the rotation restriction by the rotation restriction mechanism, Suction, compression, and discharge are performed, and it is characterized in that a recessed portion (14) is provided on the end surface of the roll body (4a) opposite to the mirror plate (4b), and a connection recessed portion (14) and the back surface of the mirror plate (4b) are provided. communication pathway (15).

Description

scroll compressor

technical field

The present invention relates to a scroll compressor. In the scroll compressor, a fixed scroll member and an orbiting scroll member are meshed to form a compression chamber therebetween. The fixed scroll member and the orbiting scroll member are formed from The mirror plate erects the scroll body, and when the orbiting scroll member rotates in a circular orbit while the rotation is restricted by the rotation restriction mechanism, the compression chamber moves while changing the volume to perform suction, compression, and discharge.

technical background

As hermetic compressors for refrigeration and air conditioning, there are reciprocating, rotor, and scroll compressors, all of which are used in the field of refrigeration and air conditioning for home use and business use. Currently, developments are being made to make use of the respective characteristics in terms of cost, performance, and the like.

Among them, compressors in which a compression mechanism and an electric mechanism are accommodated in a container are represented by so-called hermetic compressors that are soundproof and easy to maintain, and scroll compressors and rotary compressors are the mainstream. In a scroll compressor, a fixed scroll member and an orbiting scroll member are generally meshed to form a compression chamber between the two. On the basis of the rotation restriction by the rotation restriction mechanism, when the rotating scroll part rotates along a circular orbit, the compression chamber moves while changing the volume to perform suction, compression and discharge. A predetermined back pressure is applied to the outer peripheral portion and the back surface of the scroll wrap, so that the orbiting scroll does not separate from the fixed scroll and fall over.

An example of a conventional scroll compressor is shown. Fig. 7 is a sectional view of a scroll compressor. The refrigerant gas sucked from the suction pipe 1 passes through the suction chamber 3 of the fixed scroll member 2 composed of the wrapping body 2a and the mirror plate 2b, and is enclosed in the orbiting scroll which can be formed with the wrapping body 4a and the mirror plate 4b. The compression chamber 5 in which the part 4 engages, towards the center, reduces its volume while being compressed and discharged through the discharge opening 6 . The back pressure chamber 8 formed surrounded by the fixed scroll 2 and the bearing 7 needs to always have a back pressure that does not cause the orbiting scroll 4 to separate from the fixed scroll 2 at all times. However, if the back pressure is excessive, the orbiting scroll 4 is strongly pressed against the fixed scroll 2, resulting in abnormal wear of the scroll sliding portion or an increase in input. Therefore, it is necessary to always keep the back pressure constant. Therefore, a back pressure adjustment mechanism 9 is provided. The back pressure adjustment mechanism 9 is provided with a valve 11 on the passage 10 communicating with the suction chamber 3 through the interior of the fixed scroll member 2 from the back pressure chamber 8, and if the pressure in the back pressure chamber 8 is higher than the set pressure, the valve 11 is opened. , the oil in the back pressure chamber 8 is supplied to the suction chamber 3, and the back pressure chamber is maintained at a constant intermediate pressure. The above-mentioned intermediate force is applied to the back surface of the orbiting scroll member 4 to suppress the occurrence of overturning during operation. If it falls over, the fixed scroll 2 and the orbiting scroll 4 will separate, and leakage will occur in this part. In addition, the oil supplied to the suction chamber 3 moves to the compression chamber 5 along with the rotational movement, and serves to prevent leakage between the compression chambers.

In addition, a tip seal is attached to the tooth tip surface of the wrap portion of the scroll, and a tip seal groove for supplying lubricating oil to the back surface of the tip seal is formed, and the tip seal is slidable with the mirror plate on the opposite side. ground contact, reducing leakage from the tip face. According to this, back pressure is applied to the back surface of the tip seal to prevent leakage of the tip surface, and while lubricating oil passes through, an increase in sliding loss due to contact of the tip seal is prevented.

(Patent Document 1)

Japanese Patent Application Publication No. 6-288361

However, when each compression chamber formed between the fixed scroll member and the orbiting scroll member performs a compression action, when the gap between the tooth tip surfaces of each wrap portion expands, there is a possibility that the leakage increases from here, Issues that cause performance degradation. In addition, when the gap between the tooth tip surfaces of each wrap portion is narrowed, there is a problem that the tooth tip surfaces come into strong contact due to thermal strain or pressure deformation during overload, causing sticking and abnormal wear.

In addition, when carbon dioxide is used as a refrigerant, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than that of a conventional refrigeration cycle using Freon as a refrigerant. Therefore, when each compression chamber formed between the fixed scroll member and the orbiting scroll member performs a compression action, leakage from the tooth tip surface of each wrap portion further increases, resulting in a problem that the performance decreases.

In addition, it is difficult to properly control the amount of lubricating oil supplied to the back of the tip seal. There may be excessive supply of lubricating oil to the compression chamber through the back of the tip seal, causing the refrigerant to overheat and reduce performance, or due to the type of parts. The increase of the increase and the increase of the processing steps cause the problem of lower productivity. In addition, when carbon dioxide is used as a refrigerant, the pressure difference between the discharge pressure and the suction pressure of the compressor is about 7 to 10 times higher than that of a conventional refrigeration cycle using Freon as a refrigerant. Therefore, the amount of lubricating oil that enters the compression chamber increases, causing a further decrease in performance.

Therefore, in view of the above conventional problems, the present invention aims to provide a scroll compressor having high efficiency and high reliability while having a simple and low-cost configuration.

Contents of the invention

According to the scroll compressor according to the first embodiment of the present invention, a fixed scroll member with a first scroll body standing upright from a first mirror plate and a second scroll body standing up from a second mirror plate are provided in a hermetic container. The orbiting scroll member of the scroll body portion, the shaft that rotates the orbiting scroll member, and the bearing supporting the shaft, engage the fixed scroll member and the orbiting scroll member to form a compression chamber between them, A back pressure chamber is formed surrounded by the above-mentioned fixed scroll member and the above-mentioned bearing, and the lubricating oil retained in the lower part of the hermetic container passes through the passage formed inside the above-mentioned shaft, and is decompressed at the orifice installed in the orbiting scroll member. After that, it is supplied to the above-mentioned back pressure chamber, and a back pressure adjustment mechanism is provided on the passage communicating from the above-mentioned back pressure chamber through the inside of the above-mentioned fixed scroll member and the suction chamber. In the above-mentioned back pressure adjustment mechanism, a valve is provided. If the back pressure chamber If the pressure in the back pressure chamber is higher than the set pressure, the valve is opened, the oil in the back pressure chamber is supplied to the suction chamber, and the back pressure chamber is maintained at a constant intermediate pressure. When rotating along a circular orbit on the basis of self-rotation limitation, the compression chamber moves while changing its volume to perform suction, compression, and discharge. It is characterized in that a recess is provided at the front end of the second scroll body portion of the orbiting scroll member The portion is provided with a communication path connecting the recessed portion and the back surface of the second mirror plate.

According to the present embodiment, since the lubricating oil supplied to the compression chamber lubricates the tooth edge surfaces, blocking and abnormal wear do not occur. In addition, the lubricating oil supplied to the compression chamber also functions as a seal oil, which can reduce leakage from the tooth tip surface of the wrap portion. In addition, since the tip seal does not need to be provided, the number of parts does not increase, and the cost can be kept low.

In a second embodiment of the present invention, in the scroll compressor based on the first embodiment, a recessed portion is formed on the inner peripheral side of the orbiting scroll member, and the recessed portion opens to a compression chamber.

According to this embodiment, since more lubricating oil is supplied to the inner peripheral side of the orbiting scroll member, the sealing performance of the compression chamber on the inner peripheral side of the orbiting scroll member can be further improved, and the pressure from the wrap portion side can be improved. Wall leakage reduction effect.

In a third embodiment of the present invention, in the scroll compressor based on the first embodiment, a recess is formed on the outer peripheral side of the orbiting scroll, and the recess opens to the compression chamber.

According to this embodiment, since more lubricating oil is supplied to the outer peripheral side of the orbiting scroll member, the sealing performance of the compression chamber on the outer peripheral side of the orbiting scroll member can be further improved, and the airtightness from the side wall of the wrap portion can be improved. Effect of leakage reduction.

In the fourth embodiment of the present invention, in the scroll compressor based on the second or third embodiment, in the compression chamber on the opening surface of the recessed portion, the wrap of the orbiting scroll member forming the compression chamber Between the two contact points of the body portion and the wrap portion of the fixed scroll, along the length of the wrap of the orbiting scroll, the length of the opening surface of the concave portion facing the compression chamber is shortened.

According to this embodiment, since the compression chamber with the opening of the recess does not communicate with the compression chamber formed on the discharge side or the compression chamber formed on the suction side, the leakage between the compression chambers can be minimized. .

In a fifth embodiment of the present invention, in the scroll compressor based on the first embodiment, an HFC-based refrigerant or an HCFC-based refrigerant is used as the refrigerant.

According to this embodiment, the lubricating oil supplied to the compression chamber can be appropriately controlled, and a high-efficiency scroll compressor can be provided.

In a sixth embodiment of the present invention, in the scroll compressor based on the first embodiment, carbon dioxide is used as the refrigerant.

According to this embodiment, even when the pressure difference is about 7 to 10 times higher than that of the conventional refrigeration cycle using Freon as the refrigerant, the lubricating oil supplied to the compression chamber can be appropriately controlled, and high efficiency can be provided. scroll compressors.

Description of drawings

Fig. 1 is a sectional view of a scroll compressor showing one embodiment of the present invention.

Fig. 2 is an enlarged view showing an orbiting scroll and a recess according to an embodiment of the present invention.

Fig. 3 is a compression stroke diagram showing a scroll compressor according to an embodiment of the present invention.

4 is a cross-sectional view showing a position of the tip seal during operation when it is inserted into the tip seal groove.

Fig. 5 is a diagram showing a compression stroke of a scroll compressor in the presence of tip seals.

Fig. 6 is a graph showing the relationship between the pressure difference and the amount of lubricating oil.

Fig. 7 is a sectional view showing a conventional scroll compressor.

Detailed ways

1-3 show a first embodiment. In this figure, in order to clarify the difference between the scroll compressor of this embodiment and the conventional scroll compressor, the same reference numerals are assigned to the same or functionally equivalent components as in FIG. 7 . Lubricating oil stored in the lower portion of the hermetic container passes through a passage 13A formed inside the shaft 13 , is depressurized by an orifice 12 mounted in the orbiting scroll 4 , and is supplied to the back pressure chamber 8 . In addition, a recessed portion 14 is provided at the front end of the wrap portion 4 a of the orbiting scroll member 4 , and a communicating passage 15 is provided that communicates between the recessed portion 14 and the rear surface of the mirror plate 4 b. In addition, in this embodiment, since the suction pipe 1 and the suction chamber 3 overlap with the back pressure adjustment mechanism 9, they are conveniently divided into left and right sides around the axis 13 and shown in the figure.

According to this configuration, since the lubricating oil supplied from the recessed portion 14 is sealed in the compression chamber 5 and moves toward the center, the wrapping of the orbiting scroll 4 that strongly contacts the tooth tip surface due to thermal strain and pressure deformation during overload The central part of the body part 4a lubricates the tooth tip surface to prevent adhesion and abnormal wear. In addition, the lubricating oil supplied from the recessed portion 14 also functions as a seal oil, and it is possible to reduce leakage from the tooth edge surface of the wrap portion.

In addition, since more lubricating oil is supplied to the compression chamber 51 inside the opening of the recess 14 , the effect of reducing leakage from the side wall of the wrap portion of the compression chamber inside the opening of the recess 14 can be enhanced.

In addition, when the recessed portion 14 is formed on the outer peripheral side of the orbiting scroll member 4 and opens to the compression chamber 5 (not shown), since the lubricating oil is supplied more to the compression chamber 52 outside the opening of the recessed portion 14 Therefore, the effect of reducing the leakage from the side wall of the wrap portion of the compression chamber outside the opening of the recessed portion 14 can be enhanced.

In addition, in the compression chamber 5 located on the opening surface of the recessed portion 14, the wrap portion 4a of the orbiting scroll member 4 forming the compression chamber 5 and the wrap portion 2a of the fixed scroll member 2 are configured to be in contact with each other. Between the points, along the length of the wrap of the orbiting scroll member 4 , the length 14 a of the opening surface of the recessed portion 14 toward the compression chamber 5 is shortened. In this case, since the compression chamber 5 opened by the concave portion 14 does not communicate with the compression chamber or the discharge space 5a formed on the discharge side than the compression chamber 5, and the compression chamber 5 opened by the concave portion 14 does not communicate with the compression chamber 5 formed on the suction side. The compression chamber or the suction space 5b on the side communicates with each other, so the lubricating oil can be supplied to the compression chamber 5 while minimizing the leakage between the compression chambers.

4 and 5 show a second embodiment. In a scroll compressor using R410A which is an HFC-based refrigerant, the amount of oil supplied to the compression chamber in the case of providing a communication passage 15 that supplies lubricating oil to the tip of the blade will be described. The sealing groove 16b is supplied. The tip seal 16a inserted into the tip seal groove 16b approaches the outer peripheral side of the tip seal groove 16b due to the pressure difference between the compression chamber 51 on the inner peripheral side and the compression chamber 52 on the outer peripheral side. A gap 17a may be formed between the compression chambers 51 on the inner peripheral side.

Furthermore, it is considered that between the two contact points 18a, 18b of the wrap body portion 4a of the orbiting scroll member 4 forming the compression chamber 5 and the wrap body portion 2a of the fixed scroll member 2, there is a tip seal groove 16b. The case of the communication passage 15 for supplying lubricating oil. Since the back surface of the mirror plate 4b through which the communication passage 15 communicates is filled with lubricating oil under the discharge pressure, the pressure of the lubricating oil at the position where the communication passage 15 faces the tip seal groove 16b also becomes the discharge pressure. As a result, the gap 17b on the discharge side (center side) compared to the communication passage 15 in the gap between the back surface of the tip seal 16a and the tip seal groove 16b is filled with exhaust gas, and the suction side ( The gap 17c on the outer peripheral side) is filled with lubricating oil coming through the communication passage 15.

That is, lubricating oil flows from the mirror plate 4b through the communication passage 15 toward the suction-side gap 17c between the back surface of the tip seal 16a and the tip seal groove 16b, and supplies the lubricating oil to the compression chamber 5.

In addition, the pressure in the compression chamber 5 changes from the suction pressure to the discharge pressure as it rotates. However, since the lubricating oil coming out through the communication passage 15 is the discharge pressure, only when the pressure of the compression chamber 5 is lower than the discharge pressure, it will flow to the compression chamber 5. 5 supply lubricating oil.

In consideration of the above, the result of sorting out the amount of lubricating oil supplied to the compression chamber 5 with respect to the length multiplied by the pressure difference between the internal pressure of the compression chamber 51 and the discharge pressure is shown in FIG. 6 . Of the two contact points 18a, 18b of the wrap portion 4a of the orbiting scroll 4 and the wrap portion 2a of the fixed scroll 2 of the chamber 5, the contact point 18b along the suction side (outer peripheral side) and the communication path The length of the wrap portion 4a of the orbiting scroll portion 4 between 15.

It can be seen from FIG. 6 that although the length of the lap portion 4a of the orbiting scroll portion 4 between the contact point 18b along the outer peripheral side and the communication passage 15, which contributes to leakage, is multiplied by the The amount of pressure difference between the pressure and the discharge pressure is proportional. However, when the tip seal 16a is provided, the length contributing to leakage cannot be freely adjusted.

Therefore, by determining the length 14a of the opening of the compression chamber 5 of the recessed portion 14, the lubricating oil supplied to the compression chamber can be appropriately controlled in accordance with the relationship shown in FIG. 5 . As a result, since leakage can be prevented without deteriorating performance due to overheating of the refrigerant, and a required amount can be arbitrarily determined and supplied as lubricating oil for sliding parts, a high-efficiency scroll compressor can be provided.

In addition, even when the refrigerant is carbon dioxide, which has a pressure difference about 7 to 10 times higher than that of the conventional refrigeration cycle using Freon as the refrigerant, it is possible to properly control the lubricating oil supplied to the compression chamber, and it is possible to provide High efficiency scroll compressor.

Possibility of industrial use

The scroll compressor of the present invention can be used as a hermetic compressor used in the field of refrigeration and air conditioning for household and business use.

Claims (5)

1. A scroll compressor has a fixed scroll member (2) that erects a first scroll body (2a) from a first mirror plate (2b) in a sealed container, and a fixed scroll member (2) that stands up from a second mirror plate (2b). (4b) The orbiting scroll member (4) that erects the second scroll body portion (4a), the shaft (13) that makes the above-mentioned orbiting scroll member (4) rotate, and the bearing (13) that supports the above-mentioned shaft (13) 7), The above-mentioned fixed scroll member (2) and the above-mentioned orbiting scroll member (4) are meshed to form a compression chamber between the two, A back pressure chamber (8) is formed surrounded by the above-mentioned fixed scroll member (2) and the above-mentioned bearing (7), The lubricating oil retained in the lower part of the sealed container passes through the passage (13A) formed inside the shaft (13), is depressurized by the orifice (12) installed in the orbiting scroll (4), and is supplied to the The above-mentioned back pressure chamber (8), A back pressure adjustment mechanism (9) is provided on the passage (10) communicating with the suction chamber (3) from the back pressure chamber (8) through the interior of the fixed scroll member (2), In the back pressure adjusting mechanism (9), a valve (11) is provided. If the pressure in the back pressure chamber (8) is higher than the set pressure, the valve (11) will be opened, and the engine oil in the back pressure chamber (8) will be sent to the The above-mentioned suction chamber (3) supplies and maintains a constant intermediate pressure in the above-mentioned back pressure chamber (8), When the above-mentioned orbiting scroll member (4) is rotated along a circular orbit on the basis of the rotation restriction by the rotation restriction mechanism, the compression chamber moves while changing the volume to perform suction, compression, and discharge. It is characterized in that, A recessed portion (14) is provided at the front end of the second scroll body portion (4a) of the orbiting scroll member (4), A communication path (15) is provided for connecting the above-mentioned recessed part (14) and the back surface of the above-mentioned second mirror plate (4b). 2. The scroll compressor according to claim 1, wherein the recessed portion is formed on the inner peripheral side of the orbiting scroll member, and the recessed portion opens to the compression chamber. 3. The scroll compressor according to claim 1, wherein the recessed portion is formed on the outer peripheral side of the orbiting scroll member, and the recessed portion opens to the compression chamber. 4. The scroll compressor according to claim 1, wherein an HFC refrigerant or an HCFC refrigerant is used as the refrigerant. 5. The scroll compressor according to claim 1, wherein carbon dioxide is used as the refrigerant.

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